1. Field of the Invention
The present invention relates to a technique for controlling at least part of progress of a video game played on each of a plurality of player terminals, which a plurality of players respectively operate, via a communication network.
2. Description of the Related Art
Heretofore, various kinds of so-called network delivery type games are presented. Such a network delivery type game is supplied to a mobile communication terminal such as cellular phone terminal via a communication network such as the Internet. In such a network delivery type game, there are various games such as a role playing game as the video game (RPG; that is, a game in which a player plays a role of a character in a world of the game, and accomplishes a predetermined object while enjoying a process that the character grows through various experiences), for example.
Further, heretofore, there is a game in which positional information is used for control of progress of the game when the game is provided to a mobile communication terminal (for example, see Japanese Patent Application Publication No. 2001-96069 and Japanese Patent No. 3,767,741).
Japanese Patent No. 3,767,741 discloses that positional information of a player obtained by means of measurement using a global positioning system (GPS) is used as data for a game.
Further, Japanese Patent Application Publication No. 2006-61612 discloses a mechanism in which in a video game executed in a mobile communication terminal such as a cellular phone terminal and a personal handyphone system (PHS), when a player character operated by a player comes down to crunch time mainly in a battle scene, by transmitting relief appeal to other players, other player character(s) operated by other player(s) who reply the relief appeal are allowed to take part in the battle, whereby the video game can proceed while players are in cooperation with each other.
The conventional technique as described above discloses that the video game can proceed while players who do not know each other are in cooperation with each other, or the contents of the video game is changed depending on positional information of the player. However, in this technique, there is a limitation with respect to the player to which cooperation can be appealed, and the positional information is utilized only to select specific one among multiple patterns of characters, items and scenarios that are prepared in advance. Therefore, there has been a problem that diversification of the game contents has a limitation.